/Engine/Plugins/Runtime/MassEntity/Source/MassEntity/Public/MassSubsystemAccess.h
void SetSubsystemRequirementBits ( const [FMassExternalSubsystemBitSet](API\Plugins\MassEntity\FMassExternalSubsystemBitSet) & InConstSubsystemsBitSet, const [FMassExternalSubsystemBitSet](API\Plugins\MassEntity\FMassExternalSubsystemBitSet) & InMutableSubsystemsBitSet )